Scanning device for television



March M1935 E. L. KOCH 2,6345% SCANNING DEVICE FOR TELEVISION Filed' Feb. 6, 1932 2 Sheets-Sheet 2 ENVENTOR Earl Ljfaclz ATTORNEY Patented Mar. 17, 1936 UNITED STATES PATENT OFFICE SCANNING DEVICE FOR TELEVISION York Application February 6, 1932,. Serial No. 591,296.

8 Claims.

This invention relates to improvements in scanning devices for television, and has for its object the production of a simple and cheap scanner that can be used at either the television transmitter or receiver.

A further object of the invention is to provide a scanner which does not require any motor for its operation and in which the parts are small and light in weight and therefore readily actuated by relatively feeble currents.

A further object is to provide a scanner that may be used either with a lens or with a mirror, as more fully hereinafter described.

Other objects will be apparent from the following specification, the invention consisting substantially in the construction, combination, location and relative arrangement of'parts, all as will be more fully hereinafter set forth and shown by the accompanying drawings and finally pointed out in the appended claims.

Most known systems of television employ a Nipkow disc for scanning the object to be televised and for forming the received image at the receiving station. Such discs must be accurate especially in respect to the size and location of the holes therein and the discs at the receiving stations must be accurately syncronized with the discs at the transmitter. 'Motors of considerable power are required at both the transmitter and the receiver and the noise made by these motors in receiving sets is very objectionable, especially when the televised picture is synchronized, with the radio broadcast of speech or music which is received on the same set or in the same room with the television receiver.

The present invention eliminates the motors heretofore used and substitutes for the disc a mechanism which is relatively simple and easy to construct. The improved scanner weighs but a fraction of the combined weight of a disc and motor as employed in known systems and when employed in receiving sets is easily synchronized with the corresponding device at the transmitter.

The invention is particularly adapted to the use a of a system employing two sources of alternating an amplifier for the television wave and also tofilters and amplifiers for the 10 and 500 cycle currents respectively.

The utilization of the 10 and 500 cycle currents to operate the scanner at the receiver is hereinafter described.

It will be understood that the foregoing disclosure of a television system forms the subject matter of another invention and is disclosed here only in sufiicient detail to enable the operation of the device described herein to be understood.

In the accompanying drawings:

Figure 1 is an isometric diagrammaticview of the television scanner constituting this invention;

Figure 2 is a front elevation of the device, Figure 1; and

Figure 3. is a View on the line 33, Figure 2, together with a diagrammatic representation of other parts of the television receiving apparatus.

The size of the scanner will depend upon whether it is to be used for transmitting or receiving, but an approximate idea of the size of the complete scanner will be gained from the fact that a receiving scanner would have a mirror l0 approximately A in diameter, all of the other parts being in relative proportion, from which it will be observed that the complete receiving outfit as shown in Figure 2 is about 1" wide and 2% long. It is therefore exceedingly compact and may be readily built into an ordinary receivme set.

The numeral H!- denotes the mirror mounted in the horizontalpivots l I 12 which are mounted in a light, rectangular frame I3, which is in turn mounted in vertical pivots indicated at l4, l5. The frame of the mirror which maybe of any suitable construction, and which is preferably made of magnetic material such as soft iron, has rigidly thereto secured armatures l6, I! which project into the magnet coils l9, 2!].

Rigidly secured to the rectangular frame, at least the top of Which is preferably of magnetic material, are projecting armatures 2|, 22 which extend into coils 23, 24.

The coils l9 and 20' are supported upon a pair,

site sign, oscillatory scanning means carried by said framework, said means including four armatures extending into the air gaps between the polar extensions of said magnets, and electrical means adjacent said armatures to cause them to oscillate.

5. A scanner comprising a movable member adapted to move a beam of light, an oscillatory frame in which said member is free to oscillate, actuating means including a magnetic polarizing system comprising four pairs of opposed poles forming four air gaps having a substantially constant magnetic flux therebetween, two of said air gaps being adjacent said member and two adjacent said frame, said member and said frame each having two armatures adapted to oscillate between the opposed poles adjacent respectively said member and said frame, and coils adjacent said movable armatures and adapted to produce a magnetic-flux of varying sign therein, thereby causing said armatures together with said movable member and said oscillating frame to oscillate at a predetermined rate.

6. A scanner comprising a support, a frame mounted to oscillate therein, a scanning member mounted to oscillate in said frame, means adapted to oscillate said frame and member in the same plane but at right angles to one another thereby causing two degrees of motion to be imparted coincidentally to said scanning member, said means comprising a pair of magnets mounted on said support, each magnet having four polar extensions opposed to form two substantially constant flux magnetic air gaps, each gap comprising a pair of poles of opposite sign, said frame and said scanning member each having a pair of armatures, one of said pair of armatures extending into the air gaps between the polar extensions of one of said pair of magnets, the other of said pair of armatures extending into the air gaps of the other of said pair of magnets, and electromagnetic means adjacent each of said armatures to cause same to oscillate.

7. A scanner comprising a support, a pair of magnetic members supported thereby, each of said magnetic members having two pairs of oppositely opposed poles for producing magnetic fields of substantially constant flux, a frame mounted on said support, armatures secured to said frame and extending between said two pairs of opposed poles of one of said pair of magnetic members, a member mounted in said frame, armatures secured to said member and extending between said two pairs of opposed poles of the second of said pair of magnetic members, both of said magnetic members producing a constant magnetic field thereby creating a polarized magnetic system with respect to all of said oppositely opposed poles and associated armatures attached to said frame and member mounted therein, and means for independently causing said frame and said member mounted therein to be oscillated.

8. A scanner comprising a support, a frame mounted to oscillate therein, a scanning member mounted to oscillate in said frame, two projecting armature pole pieces each for said scanning member and said frame, means including a pair of magnets of constant field strength secured to said support, each magnet carrying two pairs of opposed poles and forming thereby two air gaps, the armature pole pieces of said frame adapted to operate between the two air gaps of one of said pair of magnets and the armature pole pieces of said scanning member adapted to operate between the two air gaps of the other of said pair of magnets, and coils adjacent the armature pole pieces of said scanning member and said frame for the purpose of causing said scanning member and said frame to be oscillated, each independently from the other.

EARL L. KOCH.

ay 19, 1936. T. LINDENBERG THEATER BUILDING Filed Oct. 5, 1934 2 Sheets-Sheet 1 

